Step 4: Enable band, low or high-pass filtering
Filters and thresholding settings are found on the Advanced Settings tab. AudioMoth firmware currently supports three frequency filters: low-pass, band-pass and high-pass.
The band-pass filter will let you set the upper and lower frequencies for recordings produced by your device. If you set the slider to 10 kHz and 19.1 kHz, recordings will only include audio data between these two frequencies, discarding the rest.
The low-pass filter works similarly, with the slider selecting a frequency, below which will be recorded. Likewise, if the high-pass filter is selected, audio higher than the slider value will be recorded.
Configuration app guide
Step 1: Download and install your platform's configuration app
Go to the app download page and download the installer for the relevant operating system.
Step 2: Add recording periods to the configuration
Enter up to 4 periods in which the device will record and then sleep repeatedly until the period is over.
Step 3: Customise recordings
Set the sample rate, gain and length of the recordings you wish to collect. The app will then calculate the energy and storage consumption of your configuration.
Step 5: Enable amplitude threshold recording
Also included in the Advanced Settings tab is amplitude thresholding. When enabled, your AudioMoth is able to produce much smaller files which contain just the audio above the chosen threshold. The gaps between these periods are removed to minimise the space each files takes up, however it is possible to regain these gaps and see when the sounds actually occurred within the recording.
Step 6: Additional settings
The final tab also includes two advanced settings. The first is whether or not to require an acoustic chime before following the recording schedule in CUSTOM mode. If this is checked, then when switched to CUSTOM, even if the time has been set, the AudioMoth will wait for an acoustic chime before commencing the configured schedule.
The second setting is whether to use the voltage range of NiMH/LiPo batteries in order to calculate the current battery level. This battery level is displayed when a device is switched to CUSTOM, before connection over USB has been established.
Step 6: Expand amplitude threshold recordings
To expand recordings produced by amplitude thresholding, open the expansion window through the File menu. From here you can put a limit on the size of the expanded recordings. If the expansion produces a file larger than this limit, it will be split into a new file. For example, if you record for 5 hours with amplitude threshold recording enabled, expanding this file with no limit will produce a 5 hour long WAV file.
Once a limit has been set or removed, select the recordings to expand. These are easily identified by a 'T' at the end of the recording name. Select either a folder which contains recordings, or the amplitude threshold recordings directly. Click Expand Recordings and the app will expand each relevant file and place the expanded files in the same directory as the original (keeping the original, unexpanded file).
Step 7: Connect AudioMoth device
Set the switch on the side of your AudioMoth device to USB/OFF and attach it to your computer via USB.
Ensure the device has batteries inserted or the time set along with the configuration will be lost when the device is disconnected and it loses power.
Step 8: Verify connection
Without a successful connection to an AudioMoth device, the configuration app will display a greyed out time, ID and battery level.
When you have successfully connected to your AudioMoth, the device information will no longer be greyed out and the clock should tick upwards from 01/01/1970.
Each AudioMoth possesses an inbuilt clock, used to record at scheduled times and to name recording files. As the clock cannot advance when the device is without battery power, a start time must be given.
Configuring your device will set the start time to your machine's current time in UTC.
Make sure the clock is set before each deployment. Either using this application or one of the chime-based smartphone apps.
Without the clock set, an AudioMoth in CUSTOM mode will not make any recordings.
Step 9: Apply configuration to device
Once device is connected, the clock display should begin to update. Click "Configure AudioMoth" to apply configuration. From firmware version 1.5.0 onwards, AudioMoth will retain these configuration settings even when power is lost. If the batteries are removed, ensure you set the clock before deploying as it is lost when power is lost.
Updated clock times are presented in UTC to remain consistent across timezones.
Configurations can also be saved to distribute or for later use. Save or load a configuration from the File menu.